Model-potential calculations of wavelengths, transition probabilities and lifetimes for core-excited quartet levels of Be II

A non-local model potential nu M , which approximates the interaction of the 1s and nl electrons in 1snl 3 L levels of Be III to high accuracy, is used to construct an effective two-electron Schrodinger equation for 1s2snl 4 L and 1s2pnl 4 L core-excited levels of Be II. Wavefunctions for quartet levels of Be II are found by a configuration-interaction expansion in terms of anti-symmetrised products of eigenfunctions of nu M and wavelengths, transition probabilities and radiative lifetimes are calculated. Some outstanding lines in the beam-foil spectrum of beryllium are discussed.